The cosmonauts I have spoken with personally have said the ISS stinks of human bodies and other things. It's also very noisy 24 by 7, and there is constant air movement. Three things they did not expect.

Every sound is transmitted across the entire structure. There's no foundation or outside air for vibrations to attenuate into so sound travels very easily.

What other good stories have you heard from them?

I asked an astronaut what it smells like in space. He said, “Ever been camping?”